Bladed servers, or bladed computer systems, are computing systems that provision servers or other computer resources on individual cards, or blades. There are many types of blades—server blades, storage blades, network blades, etc.—and one or more of each type of blade is typically housed together in a single structure, thus creating high-density computing systems with modular architectures, ensuring flexibility and scalability of the systems, and reducing space requirements. Server blades, along with storage, networking, and other blades, are typically installed in a rack-mountable enclosure, or chassis, which hosts multiple blades. The multiple blades share common resources such as cabling, power supplies, and cooling fans.
The telecommunications industry has been using blade server technology for many years. More generally, the condensed blade server architecture benefits people and businesses that: (1) use the Internet to generate revenue and to provide services to customers; (2) are moving some of their business processes to the Web; and/or (3) need the flexibility to deploy Internet-edge applications in their own data center. Because of recent developments in technology, blade servers are now used for applications such as Web hosting, Web caching, and content streaming.
In Web caching applications, frequently-requested Web content is stored closer to the user, thus allowing for quicker retrieval of objects by the user and reducing the time and bandwidth required to access the Internet. Since companies and individuals are now streaming media (e.g., video and audio) to more effectively communicate both internally and externally, a massive growth of rich media content delivery on the Internet has occurred. Bladed servers are being used to meet the new demands created as a result of this growth.
Though bladed servers provide many advantages, several engineering challenges arise when using bladed servers. Among these challenges is the challenge of designing and operating a bladed system such that sufficient heat is dissipated in the limited space available in the chassis that hosts the system. Some known power limiting strategies include powering down a CPU functional unit, e.g., a floating-point unit or an on-die cache, or trading off speed for reduced power consumption in a hard drive. To address heat dissipation challenges, bladed server systems are designed within an underlying power and thermal envelope. For example, when a chassis that hosts a bladed system has a limited amount of airflow available to cool the blades (i.e., when the system can only dissipate a limited amount of heat), then the chassis is designed for a limited amount of power consumption and an associated limited performance of the blades.
Engineering challenges currently occur in bladed systems when a user wishes to increase the capacity or performance of a bladed system, i.e., increase the capacity of the system on demand. Some bladed computer systems are sold with an infrastructure in place for a specific amount of capacity based on future requirements. Initially, only a portion of the system is turned on and available for the customer to use. As the user's future requirements increase, e.g., performance or memory, the user may request more capacity on demand and alter the system to increase the performance of the system.
Prior solutions required a user to purchase new, additional, or upgraded hardware to add to the system. This method of increasing the capacity on demand requires an expert in hardware configuration to reconfigure the hardware.
Another known method of increasing the capacity on demand includes shipping a bladed system to a customer that includes components that are not turned on or available for use by the user of the system. For example, a typical application of this method would be to turn on an additional processor as the user's need increased. This method requires the component or processor to sit for an undetermined amount of time, and therefore, the capacity of the system to be increased in discrete units, i.e., by one or more processors.